The Caverns of Golmath are the winding tunnels beneath the dark lands of Golamer. They were the keep and home of Milcoth and Morlred.
This is also where Milcoth was defeated by Dorian in the middle of the fourth age.
Golmath was also the birthplace of gargoyles. Gargoyles were goblins merged with dragons, which Milcoth used as his main flight army.